Abstract

Intensity measurements have been made on a complex super-multiplet of normal titanium, <sup>5</sup><i>D</i>′<i>FG</i>′-<sup>5</sup><i>H</i>′<i>GF</i>′<i>DP</i>′, arising from the transition [(3<i>d</i>)<sup>2</sup>4<i>s</i>] 4<i>p</i>-4<i>d</i>, parent term <i>a</i><sup>4</sup><i>F</i>′, and on a simple super-multiplet <sup>5</sup><i>D</i>′<i>FG</i>′-<sup>5</sup><i>F</i>′ arising from the transition [(3<i>d</i>)<sup>2</sup>4<i>s</i>] 4<i>p</i>-5<i>s</i>. The intensities of the latter have been found to be practically normal, the multiplet ratios being measured as 8.95:7.00:5.30, or within 6% of the theoretical values, with no self-reversal or excitation corrections needed. The complex super-multiplet has extremely anomalous intensities, as might be expected from the fact that it contains strong <sup>5</sup><i>FH</i>′ lines and that a number of lines allowed by the selection principles and usually of considerable intensity are found to be entirely missing in its multiplets. Very few lines have normal intensity ratios to one another, and in no individual multiplet is the Sum Rule fulfilled. In the super-multiplet as a whole the fulfillment of the Sum Rule is only slightly better; the average deviation of the sums from the mean is about 15%, after an excitation correction corresponding to 2080°A for the temperature of the emitting arc has been applied. No other temperature will furnish a correction making the deviation appreciably less. Kronig’s formulas for the relative intensities of the nine multiplets hold only roughly. The measurements were made rather difficult by the relative weakness of the lines and by the presence of Cyanogen bands in their neighborhood, but results from a number of sets of plates showed very good agreement, and it is believed that the average final error is considerably under 10%.